From 8c1c918c94b443c7154d535b1f99201dc1767f97 Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Mon, 18 Oct 2004 22:01:10 +0000
Subject: r3050: Steal from Samba4 :-). Make us pass most of the new lock tests
 (except for the cancel lock which I have to add). Jeremy. (This used to be
 commit cf7f89999e0c6becd4617c812400d1e71b9c0a30)

---
 source3/locking/brlock.c | 73 +++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 56 insertions(+), 17 deletions(-)

(limited to 'source3/locking')

diff --git a/source3/locking/brlock.c b/source3/locking/brlock.c
index 4c34bd7dfd..61144eb59a 100644
--- a/source3/locking/brlock.c
+++ b/source3/locking/brlock.c
@@ -91,6 +91,28 @@ static BOOL brl_same_context(struct lock_context *ctx1,
 		(ctx1->tid == ctx2->tid);
 }
 
+/****************************************************************************
+ See if lck1 and lck2 overlap.
+****************************************************************************/
+
+static BOOL brl_overlap(struct lock_struct *lck1,
+                        struct lock_struct *lck2)
+{
+	/* this extra check is not redundent - it copes with locks
+	   that go beyond the end of 64 bit file space */
+	if (lck1->size != 0 &&
+	    lck1->start == lck2->start &&
+	    lck1->size == lck2->size) {
+		return True;
+	}
+
+	if (lck1->start >= (lck2->start+lck2->size) ||
+	    lck2->start >= (lck1->start+lck1->size)) {
+		return False;
+	}
+	return True;
+}
+
 /****************************************************************************
  See if lock2 can be added when lock1 is in place.
 ****************************************************************************/
@@ -115,7 +137,7 @@ static BOOL brl_conflict(struct lock_struct *lck1,
 		return False;
 	}
 	    
-	return True;
+	return brl_overlap(lck1, lck2);
 } 
 
 #if ZERO_ZERO
@@ -175,9 +197,36 @@ static BOOL brl_conflict_other(struct lock_struct *lck1, struct lock_struct *lck
 	    lck2->start >= (lck1->start + lck1->size))
 		return False;
 	    
-	return True;
+	return brl_overlap(lck1, lck2);
 } 
 
+/****************************************************************************
+ Amazingly enough, w2k3 "remembers" whether the last lock failure
+ is the same as this one and changes its error code. I wonder if any
+ app depends on this ?
+****************************************************************************/
+
+static NTSTATUS brl_lock_failed(struct lock_struct *lock)
+{
+	static struct lock_struct last_lock_failure;
+
+	if (brl_same_context(&lock->context, &last_lock_failure.context) &&
+			lock->fnum == last_lock_failure.fnum &&
+			lock->start == last_lock_failure.start &&
+			lock->size == last_lock_failure.size) {
+		return NT_STATUS_FILE_LOCK_CONFLICT;
+	}
+	last_lock_failure = *lock;
+	if (lock->start >= 0xEF000000 &&
+			(lock->start >> 63) == 0) {
+		/* amazing the little things you learn with a test
+		   suite. Locks beyond this offset (as a 64 bit
+		   number!) always generate the conflict error code,
+		   unless the top bit is set */
+		return NT_STATUS_FILE_LOCK_CONFLICT;
+	}
+	return NT_STATUS_LOCK_NOT_GRANTED;
+}
 
 #if DONT_DO_THIS
 	/* doing this traversal could kill solaris machines under high load (tridge) */
@@ -313,8 +362,6 @@ NTSTATUS brl_lock(SMB_DEV_T dev, SMB_INO_T ino, int fnum,
 	struct lock_struct lock, *locks;
 	char *tp;
 	NTSTATUS status = NT_STATUS_OK;
-	static int last_failed = -1;
-	static br_off last_failed_start;
 
 	*my_lock_ctx = False;
 	kbuf = locking_key(dev,ino);
@@ -344,7 +391,7 @@ NTSTATUS brl_lock(SMB_DEV_T dev, SMB_INO_T ino, int fnum,
 		count = dbuf.dsize / sizeof(*locks);
 		for (i=0; i<count; i++) {
 			if (brl_conflict(&locks[i], &lock)) {
-				status = NT_STATUS_LOCK_NOT_GRANTED;
+				status = brl_lock_failed(&lock);;
 				/* Did we block ourselves ? */
 				if (brl_same_context(&locks[i].context, &lock.context))
 					*my_lock_ctx = True;
@@ -375,24 +422,16 @@ NTSTATUS brl_lock(SMB_DEV_T dev, SMB_INO_T ino, int fnum,
 	qsort(dbuf.dptr, dbuf.dsize/sizeof(lock), sizeof(lock), lock_compare);
 #endif
 
-	tdb_store(tdb, kbuf, dbuf, TDB_REPLACE);
+	if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
+		status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+		goto fail;
+	}
 
 	SAFE_FREE(dbuf.dptr);
 	tdb_chainunlock(tdb, kbuf);
 	return NT_STATUS_OK;
 
  fail:
-	/* this is a nasty hack to try to simulate the lock result cache code in w2k.
-	   It isn't completely accurate as I haven't yet worked out the correct
-	   semantics (tridge)
-	*/
-	if (last_failed == fnum &&
-	    last_failed_start == start &&
-	    NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
-		status = NT_STATUS_FILE_LOCK_CONFLICT;
-	}
-	last_failed = fnum;
-	last_failed_start = start;
 
 	SAFE_FREE(dbuf.dptr);
 	tdb_chainunlock(tdb, kbuf);
-- 
cgit